/*
 * Copyright (C) 2010 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.List;
import javax.annotation.Nullable;

/**
 * A list multimap which forwards all its method calls to another list multimap. Subclasses should
 * override one or more methods to modify the behavior of the backing multimap as desired per the
 * <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * @author Kurt Alfred Kluever
 * @since 3.0
 */
@GwtCompatible
public abstract class ForwardingListMultimap<K, V> extends ForwardingMultimap<K, V> implements ListMultimap<K, V> {

    /** Constructor for use by subclasses. */
    protected ForwardingListMultimap() {}

    @Override
    protected abstract ListMultimap<K, V> delegate();

    @Override
    public List<V> get(@Nullable K key) {
        return delegate().get(key);
    }

    @CanIgnoreReturnValue
    @Override
    public List<V> removeAll(@Nullable Object key) {
        return delegate().removeAll(key);
    }

    @CanIgnoreReturnValue
    @Override
    public List<V> replaceValues(K key, Iterable<? extends V> values) {
        return delegate().replaceValues(key, values);
    }
}
